<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <script src="js/jquery-1.10.2.js"></script>
</head>
<body>
<div id="fff">
    <div style="width: 60%; height: 100px" id="div_clone"><span>This is the test.</span></div>
</div>
<script type="text/javascript">
    $().ready(function(){
        var $elem = $("#div_clone").clone();
       $elem.find("span").text("aaaaaaaaaaaaaaaaaaaaaaaaaaaaa");
        $("#fff").append($elem);
    });
</script>
</body>
</html>